Canadian Pat. No. 982,881 dated Feb. 3, 1976 to H. Stanzinger (corresponding U.S. Pat. No. 3,824,644 dated July 23, 1974) discloses floating docks made of a plurality of interlocking units. The interlocking means thereof consist of pins engaging through superposed eye lugs. The conical enlarged heads of the pins have two projections which come into engagement with rounded grooves in the corners of the floating units so as to thus resiliently lock the pin against inadvertent rise out of the eye lugs. Since these pins are resiliently held in locking position, they may eventually become disengaged from the eye lugs in wavy waters. If conventional bolts and nuts were used, a swimmer would need to crawl under the floating dock to hold the nut in position when a second person would screw the bolt from above. This is obviously inconvenient.